This commit addresses issue #167. Previously, in snabbdom v0.5.0,
patch(element, vnode) would always create a new element for the root.
This resulted in problems with custom elements (web components), and was
fixed in commit c091c59c59.
However, that commit resulted in bug #167. This meant that snabbdom
would have bugs with server-side rendering, where the root element would
be non-empty (it has many children, rendered on the server-side as
HTML), and the client-side rendering should reuse those existing
children (or clear all the children and recreate them again in patch()).
This commit introduces the function toVNode(elm) that deep-converts an
element (and its tree) to a VNode (and its tree), that is separately
imported and used before calling patch(). toVNode(elm) will look at the
element's attributes and gather those as data for the vnode.
Overall, this commit is important for fixing #167 and enabling
client/server-side rendering in an efficient manner
(destruction/recreation client-side is probably too expensive).
This commit makes the patching algorithm ignore `null` and `undefined`
children. This means that, whenever children are iterated, the algorithm
must check for possible `null` and `undefined` values.
Previously, patch(element, vnode) would create a new element every time
for the top-level element, unless the top-level vnode had no id and
className. This is because emptyNodeAt() would create a vnode with sel
equal to the element's tagName, NOT including id and className.
This seems to be just a small fix, however this fix was crucial to get
Web Components (custom elements) working with Cycle.js, because the
custom element's "create" callback was being called infinitely and
recursively, because snabbdom was creating the top-level element every
time, even if the sel of oldVNode and vnode were supposed to be the
same.
Tom Bakker
Andre Staltz
Simon Friis Vindum
Nuno Martins
Peter Sutherland
Caridy
teddddd
Alexandre Galays
zhulongzheng
Andrew Murray
Harry Wincup
Ray Di Ciaccio
Sylvain Prat
Garth Williams
Simon JAILLET